The invention concerns a clasp with plug especially suited to being applied to gold or fashion jewellery such as for instance bracelets, necklaces, chains and similar.
As is known one type of clasp that is frequently applied to items of gold and fashion jewellery is often called a xe2x80x9cplug claspxe2x80x9d.
This basically comprises a female element provided with first means of attaching to a first end of one of said items, which has a hole that receives a plug belonging to a male element provided with second means of attaching to the second end of the same item.
The firm yet detachable coupling of the plug of the male element within the corresponding hole in the female element, is achieved by one or more extending members that are made to flex by elastic devices and are provided with means of locking suited to connecting with corresponding means of striking belonging to the female element.
Known plug clasps of the type described above, in comparison to other known kinds of clasp, have the advantage of offering greater reliability against accidental opening. What""s more they can be made in any shape whatsoever suited to being integrated with the shape of the item they are applied to.
These clasps do nevertheless have a limitation in that the extending members and the elastic devices they work with, are all enclosed within the plug of the male element and consequently the plug cannot be produced in sizes smaller than a given minimum limit governed by the coexistence inside of the extending members and the elastic devices.
As a result, known types of plug clasp cannot be used on any items, such as necklaces or bracelets, which are somewhat small in cross-section since this would ruin the overall aesthetic appearance of these items.
To overcome these limitations and inconveniences, the depositee of this invention has registered under the same name the Italian patent for industrial invention having deposit number V196A000064 which describes an improved type of plug clasp that against equivalent, known types of plug clasp has markedly smaller cross-sectional dimensions.
To be more precise the clasp comprises a female element and a male element provided with a plug that can be fastened in a corresponding hole in the female element.
The male element contains a flexibly extending member externally operated by an actuator end, provided with means of locking that connect with corresponding means of striking belonging to the female element when the plug is fastened in the hole of the female element.
The extending member is basically L-shaped and sits in a cavity made in the body of the male element, which ends with a well that holds the shaped end of the extending member.
A pivot point is thereby created that allows the extending member to rotate when the user presses it from the outside on the actuator end.
A spring inserted in the body of the male element, having one end connected to the male element and its opposite end restrained within a hole made in the extending member, provides the latter with a flexing movement.
Together with its flexing function, the spring also performs the function of travel stop that limits the movement of the extending member while it rocks to open or close the clasp. The clasp described above has however some limitations and inconveniences.
A first inconvenience is the difficulty found when producing the well that holds the end of the extending member in the body of the male element.
Another inconvenience is the need to produce the hole in the extending member that holds the end of the elastic device. Last but not least an inconvenience is the lack of a genuine travel stop that allows to limit the rocking of the extending member inside the seat that holds it.
This invention intends to overcome these limitations and inconveniences.
In particular a first scope of the invention is to produce a plug clasp that is simpler to produce than the clasp under the aforementioned patent.
Another scope is that the clasp of the invention should also have a greater precision in its operation. Last but not least a scope is that the clasp invention be easier to assemble than similar, equivalent clasps.
Said scopes are achieved by producing a clasp for gold and/or fashion jewellery items such as bracelets, necklaces and similar that in accordance with the main claim comprises:
at least one female element and at least one male element fastened by means of attaching each to its respective end of one of said adornments;
a plug belonging to the body of said at least one male element, suited to being fastened in a corresponding hole in said at least one female element;
an extending member basically shaped in the form of an L that comprises a first part fitted in a first seat made lengthways in said plug and a second part fitted in a second seat made in the body of said male element and provided with means of locking suited to snapping onto corresponding means of striking belonging to said female element when said plug is fastened in said hole;
a shaped end belonging to said second part and protruding from the body of said at least one male element that acts as the actuator piece for the user to operate;
at least one elastic device inserted between said extending member and the body of said male element, and wherein the end of said first part of said extending member has a fork created by two arms spread apart that meet to create a seat suited to being closed across a fixed pin set crossways through said first seat of said plug, the latter being provided with an opening for introducing a tool suited to closing said arms rotating around said fixed pin.
According to a preferred form of execution, the second part of said extending member consists of a flat sheet metal body whose end is shaped to provide the fork.
The fork is created by two arms spreading apart in a V-shape that meet to create a basically ringed sectioned seat that will couple around the outside of a pin, which also has a basically ringed cross-section.
When the fork""s arms are closed by bending, achieved for instance by pliers that are introduced through the opening made in the end of the plug, the extending member remains coupled rotating around the plug.
The elastic devices consist of a coil spring restrained between the second part of the extending member and the body of the male element.
The body of the male element also has a slot from which protrudes an adjustable striking element suited to limiting the movement of the extending member inside said plug.
An advantage obtained from the clasp is that it is easier to produce since the plug does not have blind spots.
Another advantage is that the particular forked construction of the end of the extending member and the way by which it is coupled rotating around the pin, allows greater precision in the clasp""s operation.